1. Field of the Invention
The present invention relates in general to boom assemblies employed in spraying agricultural crops and more specifically, to such boom assemblies that are adapted to compensate for variations in the terrain over which they travel.
2. Description of the Prior Art
Standard equipment presently employed for spraying chemical herbicides, pesticides or the like on agricultural crops includes a vehicle for carrying a chemical storage tank and a spray boom extended transversely with respect to the vehicle. The spray boom has a plurality of spaced apart spray nozzles mounted along its length and a pump and associated spray lines transfer chemical from the storage tank to the spray nozzles.
To expedite spraying a field of agricultural crops, long spray booms are commonly employed and extend outwardly from the rear of the vehicle in cantilever fashion. A primary problem inherent in the use of such spray booms of extreme length is that the rough terrain often encountered by the vehicles upon which they are mounted makes it difficult to stabilize the booms and maintain an equal distance between the nozzles on the booms and the crops being sprayed.
Various devices for mounting a boom to a vehicle have been employed to increase the boom's stability, such as those disclosed in U.S. patents, U.S. Pat. Nos. 3,545,678, to Tangeman, 4,039,147 to Hugg and 4,197,999 to Lammers. The inventions of each of the above patents include parallel linked type systems for connecting the boom to an implement to improve the stability of the boom. The present invention provides an improved means over such prior art for controlling the spacing of the boom from the crop being sprayed as it travels over a varying terrain.